The present invention generally relates to tufting carpets, and in particular to a method and system for tufting loop pile and cut pile tufts in a backing material to form patterned carpets.
In the field of tufting carpets, it has been known to tuft carpets having spaced rows of loop pile and cut pile tufts, including the formation of loop pile and cut pile tufts in the same longitudinal tuft rows of the carpets. For example, U.S. Pat. No. 3,919,953 discloses an apparatus and method for tufting spaced rows of loop pile and cut pile tufts formed in a backing material using a multi-needle tufting machine having two transverse rows of needles with each row cooperating with a series of loop pile loopers or cut pile hooks. Still further, U.S. Pat. Nos. 5,224,434 and 5,499,588 disclose methods and apparatus for producing cut pile and loop pile tufts in the same longitudinal rows of tufting and which further provide for the shifting of the needle bars carrying spaced rows of needles to provide enhanced pattern effects such as the formation of cut and loop pile tufts in the same tuft rows.
For higher or finer gauge tufting machines, i.e., {fraction (5/32)}-{fraction (1/16)} gauge machines, however, as the spacing between the needles is narrowed for forming finer gauge carpets, problems exist whereby the cut pile hooks will tend to engage the previously formed loop pile tufts, potentially resulting in the cutting or pulling of such tufts, creating defects in the carpet. One solution that has developed for this problem has been to move the loopers and hooks so that the loopers and hooks will reach through or between their associated rows of needles to engage and pick up yarns from the opposite row of needles. For example, the cut pile hooks that are positioned below the downstream or rear row of needles are passed between the needles of the rear row of needles and the loop pile loopers to engage the corresponding needles of a first row of needles, while the loop pile loopers are passed between the needles of the first or upstream row of needles and the cut pile hooks to engage needles along the rear or downstream row of needles. However, for higher or finer gauge machines, as the spacing between the loopers is decreased, the problem still can exist whereby the knives for the cut pile hooks can be engaged or can interfere with the passage of the loop pile loops. Attempts to solve this problem by spacing the rows of needles further apart can, however, lead to additional problems with the stretching of the backing material, causing side matching problems due to the stretching and resultant necking in of the backing material as the tufts of yarn are introduced therein.
Accordingly, it can be seen that a need exists for a method and system of forming cut pile and loop pile tufts in a backing material to form patterned carpets that addresses the foregoing related and unrelated problems in the art.
Briefly, described, the present invention generally relates to a method and apparatus for forming or introducing loop pile and cut pile tufts of yarns into a backing fabric passing through a tufting zone of a tufting machine to form tufted carpets. The tufting machine generally will include first and second rows of transversely spaced needles that receive a series of yarns from a yarn source or yarn feed drive mechanism. The needles generally are spaced along needle bars at a prescribed gauge spacing, i.e., xe2x85x9 inch, {fraction (1/16)} inch, {fraction (5/32)} inch, etc., and are reciprocated into and out of engagement with a backing material passing through a tufting zone of the tufting machine for introduction of tufts of yarn into the backing material to form tufted carpets.
A looper assembly is mounted below the backing material and generally includes two spaced, transversely extending rows of loop pile loopers and cut pile hooks mounted along opposite sides of the tufting zone for the tufting machine. Typically, the loop pile loopers will be arranged in spaced series along an upstream side of the tufting zone, facing along the direction of feed of the backing material through the tufting zone, while the cut pile hooks generally will be mounted along the opposite side of the tufting zone from the loopers. Each of the loopers generally includes a shank portion attached to a looper support and a bill or forward portion extending forwardly from the shank portion toward an associated needle. The bill of each looper will engage or strike a take-off portion of its associated needle to engage and pickup a loop of yarn from the needle for forming loop pile tufts in the backing material.
Similarly, the cut pile hooks each include a shank or body portion and a throat portion that extends forwardly from the shank portion and terminates in a hooked or curved forward end. Each hook will engage an associated needle at a pickup or takeoff portion thereof so as to pickup and form loops of yarns along the throat portion of the hook. Each cut pile hook further generally will include a knife assembly associated therewith, which includes a knife or cutting blade that is moved in a reciprocal cutting motion along the throat portion of its associated hook so as to sever or cut the loops of yarn collected along the hook to form cut pile tufts in the backing material.
With the system of the present invention, the cut pile hooks and loop pile loopers generally are staggered transversely from each other with each of the loopers being aligned with a gap between each of the cut pile hooks and each of the cut pile hooks accordingly being aligned with the gaps defined between each of the loopers. As the needles penetrate the backing, the loopers and cut pile hooks will be reciprocated into engagement with their associated needles and will pass between each other such that the loopers will engage the second or rear row of needles, while the cut pile hooks will thus engage the first or forward row of needles of the tufting machine.
Further, the knives of each of the cut-pile hooks are of an opposite hand cutting to the takeoff or pickup cut pile needles of the first row of cut pile needles and will be positioned on the pickup side their associated hooks, so as to be positioned along the same side of their hook as the needle being engaged by the hook. Accordingly, during operation of the tufting machine, the loopers and cut pile hooks will tend to pass between each other and engage the opposite row of needles as the needles penetrate the backing material to form both loop pile and cut pile tufts of yarns in the backing material, as the knives of each of the cut pile hooks are moved about the reciprocating cutting motion to engage and cut the loops collected along the throat portions of their associated cut pile hooks to form the cut pile tufts.
Various objects, features and advantages of the present invention will become apparent to those skilled in the art upon a review of the following detailed description when taken in conjunction with the accompanying drawings.